diff --git a/nucleons.jl b/nucleons.jl
index 32ce4a8..7abc274 100644
--- a/nucleons.jl
+++ b/nucleons.jl
@@ -27,19 +27,19 @@ end
     divs is the number of mesh divisions so solution would be returned as a 2×(1+divs) matrix,
     shooting method divides the interval into two partitions at r_max/2, ensuring convergence at both r=0 and r=r_max,
     the other parameters are the same from dirac!(...)."
-function solveNucleonWf(κ, p, E, Φ0, W0, B0, A0, r_max, divs; shooting=true, normalize=true)
+function solveNucleonWf(κ, p, E, Φ0, W0, B0, A0, r_max, divs; shooting=true, normalize=true, algo=Tsit5())
     Δr = r_max / divs
 
     if shooting
         @assert divs % 2 == 0 "divs must be an even number when shooting=true"
         prob = ODEProblem(dirac!, [0, 1], (r_max, r_max / 2))
-        sol = solve(prob, RK4(), p=(κ, p, E, Φ0, W0, B0, A0), saveat=Δr)
+        sol = solve(prob, algo, p=(κ, p, E, Φ0, W0, B0, A0), saveat=Δr)
         wf_right = reverse(hcat(sol.u...); dims=2)
         r_max = r_max / 2 # for the next step
     end
     
     prob = ODEProblem(dirac!, [0, 1], (0, r_max))
-    sol = solve(prob, RK4(), p=(κ, p, E, Φ0, W0, B0, A0), saveat=Δr)
+    sol = solve(prob, algo, p=(κ, p, E, Φ0, W0, B0, A0), saveat=Δr)
     wf = hcat(sol.u...)
 
     if shooting # join two segments